package com.Collection;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class Main85 {
    public static void main(String[] argv) throws Exception{
        List stuff = Arrays.asList(new String[] { "a", "b" });
        List list = new ArrayList(stuff);
        list =Collections.unmodifiableList(list);
        try{
            list.set(0,"new value");
        }catch(UnsupportedOperationException e){
            Set set = new HashSet(stuff);
            set= Collections.unmodifiableSet(set);
            Map map = new HashMap();
            map = Collections.unmodifiableMap(map);
            System.out.println("集合现在是只读");
        }
    }
}
